1. Field of the Invention
This invention relates to doors characterized by a plurality of hingedly coupled sections.
More particularly, the present invention relates to sectional doors of the type especially adapted for vertical movement.
In a further and more specific aspect, the instant invention concerns improvements in the structure and methods of fabrication of doors of the above description.
2. Prior Art
Sectional doors of the type disposed for vertical movement are exceedingly well-known. Exemplary is the conventional garage door commonly used in connection with single and multiple family residential structures. Doors of the immediate character also have broad application in connection with commercial facilities such as service centers and warehouses.
A sectional door commonly includes a plurality of horizontally extending, elongate sections. The several sections are vertically aligned, the lower edge of each section being hingedly affixed to the upper edge of the successive section. The ends of each section are secured to a respective guiding track on either side of a doorway. Generally, the guides extend vertically along the doorway and translate to extend horizontally at an overhead location.
Traditionally, door sections are constructed of wood or metal. Adjacent sections are joined by several pintle type hinges, the leaves of which are secured by appropriate mechanical fasteners to the rear or interior side of the sections. The tracks are usually fabricated of steel "C" channel stock with an arcuate transition intermediate the vertical and the horizontal runs. Rollers, carried upon shaves projecting from the sections, follow within the "C" channel tracks.
The door structure usually includes one or more counter balancing springs which assist in lifting and also function to dampen movement during closing. Frequently, the door is fitted with a power driven accessory device for opening and closing. Usually including a reversible electrically rotated lead screw coupled to the upper most section, the device raises and lowers the door in response to manually operable switch means.
Doors of the foregoing character have been continuously produced in substantial quantities for an extended period of time. Nevertheless, the structure has never proven to be entirely satisfactory. Especially noted are characteristics which represent conceivable safety hazards, present potential for structural failure and detract from appearance.
The hinges, the track and roller assembly, and the springs are representative of the potential for structural failure. Comparably, these items require vigilant periodic attendance for purposes of maintenance and adjustment. Also noted in this regard are accessory items such as electrically operated opening and closing devices. In general, the foregoing are causes of annoyance and inconvenience for the user. The breakage of the spring, however, can have serious effects. Considering the physical size and the stored energy, a fractured spring can propel fragments with a shrapnel-like effect upon animate and inanimate objects in the environment.
The inherent design configuration of the conventional prior art sectional door is also a source of concern. Specifically observed are the areas of thermal insulation and ventilation. The insulation value of a metal door, for example, is minimal. Further, the ever present space between the sections provides for continuous communication between the interior of the enclosure and the surrounding environment with further loss of thermal integrity and a means of ingress for airborne contaminates and particulate matter. On the other hand, the door must be at least partially raised when exterior ventilation is desired.
Another disadvantage associated with conventional prior art sectional doors is seen in the substantial cost of initial installation and of maintenance. Part of the initial cost resides in the necessity of producing and maintaining an extensive inventory in order to provide a satisfactory selection of styles for the consumer. Replacement of an entire door or even a single damaged panel is expensive. Accordingly, a door is considered a major fixture with change in decor being limited to repainting.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide improvements for sectional doors.
Another object of the invention is the provision of a sectional door which is relatively unencumbered and free from externally attached hardware.
And another object of this invention is to provide a sectional door assembly having fewer exposed operational components.
Still another object of the invention is provision of improvements which substantially reduce the potential safety hazards normally associated with vertically moveable sectional doors.
Yet another object of the instant invention is to provide a sectional door having effectively increased thermal insulation.
Yet still another object of the invention is the provision of improved guide means for supporting a vertically moveable sectional door.
And a further object of the invention is to provide an improved sectional door assembly which is substantially more conveniently and rapidly installed than prior art devices.
Still another object of the immediate invention is the provision of improvements which greatly reduce the necessity of usual accessories, such as powered operating devices.
Yet another object of the invention is to provide improvements in the methods of fabrication of sectional doors.
And yet another object of the invention is the provision of a sectional door according to the foregoing which is less expensive to manufacture and to maintain.
A further object of the invention is a provision of improvements which greatly increase the safety of a conventional garage door system.
And a further object of the invention is a provision of improvements which greatly reduce the fallout of graphite usually found with door springs.
And yet a further object of the invention is the provision of a door spring shroud.